Conventionally, two-arm robots (also referred to as “double-arm robot,” “dual-arm robot”) including two robotic arms for one supporting body are known. For example, FIG. 2 of Patent Document 1 illustrates an industrial robot including a plurality of robotic arms disposed on a support which is provided to stand on a fixed pedestal, so as to have a given difference in height position in a vertical relationship. Each of the plurality of robotic arms is configured to be horizontally rotatable and extendable independently to each other.